Closed system for volatile organic compound recycling

ABSTRACT

In the method and system of the instant invention, volatile organic compounds (VOCs) liberated in the course of solvent-based painting of a workpiece, are recovered. The atmosphere within a closed spray-booth is maintained at a fixed humidity such that vaporized water, supplied in the form of steam or nebulized water vapor, acts as a carrier for VOCs liberated in the course of spray painting or heat curing of a workpiece. The VOCs may be recovered continuously, including during the spray-painting or heat curing of the workpiece. The VOC laden, humidified air is circulated through a condenser such that VOCs dissolved in the water vapor condense and are directed to a recovery means. The water and solvent are separated, recovered and purified for re-use or placed in an appropriate container for disposal, thereby eliminating the usual practice of expelling VOC laden air into the atmosphere. The system is provided with a flame-free heat source to cure the painted workpiece and to guard against the danger of explosion.

BACKGROUND OF THE INVENTION

This invention concerns a method and system for recycling volatileorganic compounds (VOCs) used in solvent-based paints. The system andmethod is applicable whenever a closed chamber or booth is used forspray-painting a workpiece, such as a car, to eliminate venting of VOCsto the atmosphere while capturing the VOCs for recycling.

Present day paint spray-booths need to be designed to provide a safeworking environment, to prevent pollution of the atmosphere, and toenhance the quality of the product being sprayed. In general, paintspray-booths are equipped with a constant flow of air into and out ofthe spray-booth to maintain a reduced level of VOCs in the internalatmosphere. This arrangement has led to a number of attempts to reducethe level of VOCs in the exhaust air to minimize environmentalpollution. One such attempt involves the use of aqueous-based, ratherthan solvent-based paints. Such efforts have generally produced inferiorpaint results and excessively long periods for drying of the workpiece.Limiting the amount of VOCs in solvent-based paints, as reported by atleast one manufacturer, does help to reduce VOC emissions. However,substantial VOC emissions still occur when using such paints, and a morecomprehensive solution is required.

Another attempt is found in U.S. Pat. No. 4,261,707, which discloses acomplex process and system for elimination of paint solvent vapors froman automobile paint spray-booth and curing oven to maintain a healthfuland clean environment for workers in the paint booth. The process andapparatus involves vacuum assisted vaporization of solvents fromscrubber water for subsequent condensation and recovery of the solvent.

In U.S. Pat. No. 4,444,573, a method was disclosed for using ahydrotropic substance to decrease the level of an organic solvent in anair stream from a paint spray-booth. A hydrotrope is defined as achemical substance which includes an organic group chemically bonded toa polar group. The function of the hydrotrope is to increase thesolubility of a volatile solvent in water. The method involves (a)contacting of solvent laden air from a paint spray-booth with a spray ofaqueous hydrotrope, (b) extracting solvent from the aqueous hydrotropeusing an organic oil, and (c) stripping the solvent from the oil using asteam stripper followed by condensation and recovery of the solvent. InU.S. Pat. No. 4,620,858, related to the U.S. Pat. No. 4,261,707 patentdiscussed above, a method and system is disclosed which achieves contactbetween solvent from paint spray and an organic solvent absorbingliquid, followed by regeneration of the solvent absorbing liquid. Thiscontact is achieved in a chamber separate from the chamber in which thespraying operation is conducted.

In U.S. Pat. No. 4,927,437, a method and apparatus for removingparticles, including solvent droplets, from moving air in a paintspray-booth. The apparatus involves a cyclonic separator.

In the instant invention, a closed system is provided such that, ingeneral, air is not vented to the atmosphere during paint sprayoperation. Rather, a worker in the closed system is provided with anindependent source of air, such as grade D fresh air suppliedrespirators, thus complying with health and safety requirements of theOccupational Safety and Health Administration (OSHA). The use of asupplied air respirator is already mandated by OSHA (29 CFR 1910.134d1).The instant system involves direct condensation of VOCs from thehumidified paint booth atmosphere and direct condensation of solventladen water vapor, rather than vacuum assisted vaporization andsubsequent condensation. A controlled temperature and humidityenvironment for optimal painting conditions is thereby provided while atthe same time reducing environmental pollution.

BRIEF SUMMARY OF THE INVENTION

In the method and system of the instant invention, volatile organiccompounds (VOCs) liberated in the course of solvent-based painting of aworkpiece, are recovered. The atmosphere within a closed spray-booth iscontrolled at a fixed humidity such that vaporized water, supplied inthe form of steam, acts as a carrier for VOCs liberated in the course ofspray painting or heat curing of a workpiece. The VOCs may be recoveredcontinuously, including during the spray-painting or heat curing of theworkpiece. The VOC laden, humidified air is circulated through acondenser such that VOCs dissolved in the water vapor condense and aredirected to a recovery means. The water and solvent are separated,recovered and purified for re-use or placed in an appropriate containerfor disposal, thereby eliminating the usual practice of expelling VOCladen air into the atmosphere. The system is provided with a flame-freeheat source to cure the painted workpiece and to guard against thedanger of explosion.

Thus, it will be appreciated by those skilled in the art that theinstant disclosure has several objects. One object is to provide a paintspray-booth having a controlled temperature and humidity so that thoseworking in the field will no longer be at the mercy of the elements whenit comes to spray-painting a workpiece under optimal conditions oftemperature and humidity.

Another object of this invention is to provide a closed system paintspray-booth which substantially reduces emissions of volatile organiccompounds into the atmosphere.

Another object of this invention is to provide a paint spray-booth whichwill enable those working in the field to comply with local, state andfederal clean air directives while at the same time providing anefficient, cost-effective and safe working environment for those workingin the spray paint industry.

Other objects and advantages of this invention will become apparent fromthe full disclosure which follows.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a top view of the paint spray-booth of this invention.

FIG. 2 is a schematic representation of the water decontamination unitof this invention.

FIG. 2a is perspective view of an alternative representation of thewater decontamination unit of this invention.

FIG. 3 is a schematic view of the housing containing air-treatmentcomponents as it would appear viewed through the wall of the paintspray-booth to which the housing is attached.

FIG. 4 is a side sectional view of the housing containing air-treatmentcomponents as it would appear viewed from the side of the paintspray-booth to which the housing is attached.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

This invention involves a closed system spray-booth which provides athermostatically and humidistatically controlled environment forpainting a workpiece and which recovers volatile organic solventsreleased into the air within the spray-booth during spray-painting andcuring of a workpiece. The invention comprises a chamber within which aworkpiece is spray-painted and cured, and at least one associatedhousing containing air treatment components. The chamber comprises:

(a) A sealable door through which a workpiece to be painted may beconveyed into and out of the chamber, a floor, a roof and walls;

(b) at least one sealable door through which a person who willspray-paint the workpiece may enter and leave the chamber;

(c) at least one source of supplied air for the person to use whilepresent in the chamber;

(d) a means for circulating air within the closed system spray-boothsuch that the atmosphere within the booth is constantly recirculatedbetween the chamber and the at least one housing containing airtreatment components;

(e) a means for reducing or eliminating particulate matter from air asit passes from the chamber to the at least one housing containing airtreatment components;

(f) a humidistat for measuring the level of humidity in the chamber atany given time, wherein the humidistat is operationally linked with asource of water vapor located in the at least one housing containing airtreatment components such that when the humidity in the chamber fallsbelow a pre-set limit, additional water vapor is added to the airentering the chamber.

The at least one housing containing air treatment components comprises:

(g) a water decontamination unit which comprises a condenser and a meansfor directing condensate to a means for neutralizing the condensedsolvent;

(h) a source of water vapor for maintaining the interior of the chamberin a humidified state; and

(i) a thermostat regulated flame-free heat source to cure the paintedworkpiece.

Air is constantly recirculated between the chamber and the at least onehousing containing air treatment components which maintain thetemperature and humidity of the air within the chamber within pre-setlimits. The air treatment components constantly remove volatile organiccompounds released into the air during spray-painting and subsequentcuring of the painted workpiece. Only one housing containing all of theair treatment components (g), (h), and (i) need be provided while asecond housing may provide all of these elements or only element (i) toensure even heating of the workpiece.

The operation of this system and its preferred embodiments may be bestunderstood by referring now to FIG. 1. The paint spray-booth 10 of thisinvention is a sealed enclosure having four walls, a floor, a roof, atleast one sealable door for a worker to enter and leave the booth, whichmay also be a double door with an interlock to minimize escape ofinternal air, and a sealable door 11 through which a workpiece to bepainted is conveyed into the spray-booth. In operation, once theworkpiece has been brought into the spray-booth 10, the door 11 issealed and air re-circulation within the booth is begun as describedfurther below. Because the system is closed and fresh air from theoutside is not supplied during operation, a person working in the boothmust be equipped with a supplied air breathing system. Manufacturers ofsuch units exist such that a variety of different units are available.For example, Martech Services Company produces a number of differentsupplied air breathing systems which comply with OSHA requirements andwhich supply grade D air to either one or several different supplied airrespirators at the same time. Those units are equipped with alarm lightsand audible horns. In addition, in using any such system in thespray-booth of the instant invention, in a preferred embodiment, aninterlock may be provided such that unless the worker is using anoperational supplied air respirator, the interlock prevents operation ofthe spray equipment such that no VOCs can be released into the workspace until an appropriate breathing apparatus is employed.

The internal air is recirculated by positive pressure and therebyinduced to pass through a filter system 12 and into a housing 13 whichcontains air treatment components and which forms a duct system. Once aworker begins spray-painting the workpiece, such as a passenger vehicle,a piece of furniture or any other workpiece which requires a VOCsolvated paint, spray particles in the air are trapped on the filterswhich comprise the filter system 12. According to an alternateembodiment, the particles may be removed from the air by a conventionalair scrubber which forms a water and paint emulsion. This is lesspreferred because a large volume of contaminated water is therebyproduced which also contains dissolved VOCs. Once the particulates areremoved from the air, the solvent-laden air passing into the housing 13experiences a different set of conditions depending on which side of thespray-booth is being considered. As shown in FIG. 1, there is adifferent set of components on the left side as opposed to the rightside. This is a matter of choice and economy, and those skilled in theart will appreciate that the booth could operate with identicalcomponents on both sides of the booth.

In the specific embodiment shown in FIGS. 1, 3 and 4, air passingthrough the filter system 12 on the right side of the booth. Uponexiting the filter system 12 the air flow is heated, via a steamgenerator 37, to 290° F. The steam is piped from the steam generator 37through insulated piping 44 to the first steam wand 45. The 290° F.steam neutralizes many of the VOCs, transforming them into CO₂ and H₂O.The air flow then encounters condenser coils 14 which condense anyhumidity and VOCs dissolved in the water vapor as the air passes overthe coils. The condensate drains from the condenser coils 14 to a waterdecontamination unit 15 which is described further below. Thecondensation coils 14 are part of a condenser unit which is conventionalin the art of air-conditioning and therefore requires no furtherdescription here except to say that it is preferred that the coils bedisposed at an angle so that as condensate collects on the coils, itruns down the coils and drips into a receptacle for conveyance to thestorage and solvent recovery unit 15.

After dehumidification and removal of the VOCs entrained therein, theair is directed via the housing 13, which, as noted above, acts as aduct system for the air, into an area where a source of water vapor isadded to the air by a humidistatically controlled water vapor generatingdevice 16. Such devices are conventional in the art and need littlefurther description here. Such devices as humidistatically controlledsteam generators, sonic vapor generators or any like device whichefficiently produces water vapor is acceptable. A commercially availablehumidistatically controlled steam generator is produced by AUTO-FLOW asa 1400 watt, 120 volt unit (model ESU-14) and as a 2000 watt, 220 voltunit (model ESU-20). Incorporation of such a device into the paintspray-booth of this invention is therefore contemplated. Preferably, thehumidistat provides for precise control of the relative humidity withinthe booth. During the spray-paint operation, it is desirable to maintaina relative humidity in the range of about 45% to 55% relative humidity.This allows for optimal performance of the VOC based paints and providessufficient humidity in the air to allow for efficient condensation andremoval of dissolved VOCs. Those skilled in the art will appreciate thatwater additives may be included in the water, such as the hydrotropicsubstances described in U.S. Pat. No. 4,444,573, herein incorporated byreference for this purpose. During the drying cycle of the workpiece,when the temperature in the paint spray-booth is elevated to cure thepaint (see further description below), it is desirable to maintain arelative humidity in the range of about 60% to 65%. Thus, it isdesirable to equip the water vapor generating device 16 with ahumidistat that may be easily set to maintain the humidity within eitherof these preferred operating relative humidity ranges. Control of thehumidity and removal of the entrained VOCs has several additionaladvantages. Proper regulation of the humidity avoids dye-back, solventpopping and reduced lustre, which are all problems encountered inconventional paint spray-booths due to excessive humidity. In addition,proper regulation of the humidity increases the efficiency of the curecycle such that less heat needs to be supplied. Thus, in a conventionalpaint spray-booth for automobiles, typically heat is supplied by a 1.5million BTU direct fired gas furnace. In the instant invention, adequateheating may be achieved with a residential, oil-fired water heater (seefurther description below).

Once the air passes through the region in the housing 13 where watervapor is added, it is then forced into the a thermostatically controlledflame-free air-heating device 17. The device 17 may be any flame-freeair heating device. However, since such devices were not readilycommercially available, the instant disclosure provides for one suchsystem which we installed for this purpose (see further descriptionbelow). Air passing through the device 17 is heated to such an extentthat the temperature within the paint spray-booth is maintained withindesirable operating ranges both during the workpiece painting and curingcycles. During the painting cycle, the temperature is optimallymaintained between about 60° F. and 90° F., more preferably betweenabout 70° F. and 80° F. and most preferably at about 72° F. During thecuring cycle, the temperature is maintained at about 115° F. to about145° F., and most preferably at about 120° F. to about 130° F. It isdesirable that there be an air-heating unit on both sides of the paintspray-booth to maintain even heating of the workpiece, particularlyduring the curing cycle. As noted above, only one condenser and onesource of water vapor need be used on one or the other side of thebooth, although these elements may also be provided on both sides.

Once the heated air leaves the flame-free air heating device 17, it ismade to move into an air handling and fan assembly 18, mounted on top ofthe spray chamber, through a duct system 42. Additionally, to providethe least hostile environment to personnel working in the paintspray-booth 10, a carbon or charcoal filter 46 is mounted in the ductsystem 42. The filter 46 is to remove any remaining particulate matterfrom the air flow. The filter 46 is intended to be used only whenpersonnel are working in the paint spray-booth 10, and to be rotated outof the air flow when personnel are not in the paint spray-booth 10. Arotation assembly 48 is mounted inside the duct system 42. An externalhandle 51 may be provided to rotate the assembly, or the assembly may bedesigned to automatically rotate by a control unit which triggersrotation upon certain monitored events. The filter 46 is mounted to therotation assembly 48. A baffle 47 is mounted perpendicular to the filter46 on the rotation assembly 48, so that it is rotated into the air flowwhen the filter 47 is not in use. The baffle 47 maintains the same airflow rate as was present when the filter 46 was in the air flow. Thisassembly provides the source of positive pressure which causes the airtrapped within the sealed paint spray-booth 10 to circulate through thefilters and the other aforementioned components.

The air, as it reaches the assembly, is in a heated and humidifiedstate, having been stripped of VOCs. It is drawn back into the paintspray-booth to once again pick up VOCs as they are released duringeither the paint spray operation or the curing of the painted workpiece.For the purpose of the air handling system, a device such as asquirrel-cage fan operating at between about 9,000 to about 12,000 rpmis adequate. The lowest possible air movement that achieves efficientremoval of over spray and circulation of VOC laden water vapor ispreferably used to optimize even paint application. In the instantsystem, only one fan for recirculating the air is needed, as an exhaustfan which drives VOC laden air into the atmosphere is not required. Allthat is needed is about a half of one pound of positive pressure to beproduced to efficiently recirculate the air to achieve about 9,000 toabout 12,000 cu.ft/min. circulation (the internal dimensions of atypical automotive paint spray-booth are 23 ft by 14 ft by 9 ft=2898cu.ft.).

The above mentioned filter system 12 is preferably composed of aplurality of high-efficiency replaceable filter units. In one embodimentof this invention, the filter units are preferably comprised of anexpanded polystyrene “pre-filter” and a woven filter. The polystyrenepre-filter is used to trap the bulk of the paint particles as they aredrawn into the filter system 12. The relatively particulate-free air isthen drawn into the woven filter material to remove any residualparticulates. This particular arrangement is preferred because thepolystyrene material is relatively inexpensive and can be disposed as asmall volume of hazardous waste upon “meltingdown” with a small volumeof lacquer or other available solvent.

The water decontamination unit 15 can be any sealed unit in which thevarious components of the condensate from the condenser 14 can be safelystored and the entrain solvent removed from the water. According to thisembodiment of the invention, the water decontamination unit 15, is aself contained free standing unit which is shown in some detail in FIG.2, comprised of a three chambered system. The condensate from thecondenser 14 is pumped 27 into the liquid level controlled wastewatertank 19 (e.g., 5 gallon), via an inlet tube 20. While the wastewatertank 19 is filling with condensate the water and entrained solvent begintheir natural process of separation, with the less dense solventfloating to the top. The water and entrained solvents remain in thewastewater tank 19 until the level rises to that of the UV chamber 28.The UV chamber 28 preferably comprises a flat aluminum surface 23impregnated with an ultraviolet (UV) reflective material, such astitanium dioxide, and a UV light source 24 situated above the flatsurface 23. The flat surface 23 and UV light source 24 span the widthand length of the UV chamber 28. Once the level in the wastewater tank19 reaches the UV chamber 28, the water and entrained solvents spillover into the UV chamber 28. The water and entrained solvents flow overthe impregnated flat surface 23 and are simultaneously subjected to acontinuous level of UV light from the UV light source 24. The UV lightwill tend to neutralize the entrained solvents in the water. Uponexiting the UV chamber 23 the treated water and any remaining solventsflow into the feed tank 22 (e.g., 15 gallons). The treated water will bestored in the feed tank 22 until it is reintroduced into the system.

In order to remove any remaining solvents present in the treated water,the feed tank 22 is lined with a disposable solvent absorbing urethaneliner 29. The treated water will remain in the feed tank 22 until thewater level rises sufficiently to activate an outlet pump 26, via afloat activated switch 25, for example. Once activated, the outlet pump26 transfers the treated water via an exit tube 21 through a disposablefilter 43, preferably charcoal or carbon, to the upper fill compartment36 for reintroduction into the system. The disposable filters 43 tend toremove any remaining particulate matter in treated water so as tomaintain the operational integrity of the steam generators 37.

In an alternative embodiment, the water decontamination unit 15 in aself contained free standing unit is depicted in FIG. 2a. The water andentrained solvent are pumped from the condenser 14 into the wastewatertank 19. The water and entrained solvent will remain in the wastewatertank 19 until the waste and entrained solvent reach a sufficient levelto activate the wastewater tank pump 49. The wastewater tank pump 49transfers the water and entrained solvents from the wastewater tank 19into the spray manifold 50. The spray manifold 50 uniformly distributesthe water and entrained solvents over the flat aluminum surface 23,where they are treated with UV light, from the UV light source 24. Thetreated water flows into the carbon filter feed tank 22. The treatedwater will remain in the feed tank 22 until the water level risessufficiently to activate the outlet pump 26. Once activated, the outletpump 26 transfers the treated water via an exit tube 21 through adisposable filter 43, preferably charcoal or carbon, to the upper fillcompartment 36 for reintroduction into the system. The disposablefilters 43 tend to remove any remaining particulate matter in treatedwater so as to maintain the operational integrity of the steamgenerators 37.

The disposition of several of the above mentioned air-treatmentcomponents within the housing 13 is shown in greater detail in FIGS. 3and 4. These figures show air entering the housing through the filtersystem 12. Upon exiting the filter system 12 the air flow is heated bythe first steam wand 45 to 290° F. The air is forced to move upwardthrough the condenser 14 by the suction created by the fan assembly 18and the seal created by baffles 30. As moisture containing VOCscondenses on the condenser 14, it drips into the reservoir 31, fromwhich is conducted via line 20 to the water decontamination unit 15.Lines 32 and 33, for conveying coolant to and from a compressor 34 areshown.

Once beyond the condenser 14, the air passes a source of water vapor 16which distributes the water vapor into the moving air via a second steamwand 35 or like means. In one embodiment, the source of water vapor 16is a steam generator having an upper fill compartment 36, which canreceive water retrieved from the solvent recovery unit 15. The upperfill compartment 36 is connected to a lower, steam generator 37 via ahose 38. The steam generator 37 may, in addition, be equipped with awater line and a constant water level maintained by a float shutoffvalve or electronically according to methods standard in the art. Itwill be appreciated by those skilled in the art that the steam generatormay be, instead, a nebulizer or an ultrasonic generator for productionand atomized water.

Once the air passes the water vapor generator 16, it passes through theflame-free air heating device 17, which may be comprised of a series ofcoils 39 through the inside of which heated liquid is passed from aremote liquid heating unit via inlet and exit pipes 40 and 41. Withinthe housing 13, as the recirculating air is passed through the heatedcoils, the humidified air becomes heated and enters the paintspray-booth as described above. In a particular embodiment of thisinvention, the liquid heating unit is a remote oil-powered 185,000 BTUwater heater. Use of an oil fired unit is advantageous as it allows forbetter per day calculations of fuel use, although other fuel sourcessuch as natural gas, propane or wood could be employed in anappropriately adapted boiler. To the circulating water, an appropriateconcentration of polyethylene glycol or like material is added toelevate the boiling point and depress the freezing point of the water.The liquid is heated to about 238° F. and then conveyed throughinsulated 1.25 inch copper pipes to the coils internal to the flame-freeheating device 17 and from there, back to the remote heating unit. Oncethe air has passed through the flame-free heater 17, it is conductedback into the sealed chamber through duct work 42 which connects thehousing with the chamber, via the fan assembly 18.

The housing 13, and indeed the entire booth 10, may be insulated withabout 1.5 inch thick high-density foam, with an R rating of about 18 toreduce heat loss and thereby decrease the cost of heating.

It will be appreciated from the foregoing description of this inventionthat a novel, sealed paint spray-booth has been provided whichsubstantially reduces the level of VOCs emitted into the atmosphere as aresult of the use of solvent-based spray paints. In addition, it will beappreciated that in a simple and cost effective fashion, a conventionalpaint spray-booth may be equipped with the various aforedescribedcomponents so as to operate in an optimally thermostated andhumidistated environment for optimal painting performance. Thus, bothnewly manufactured and retrofitted pre-manufactured or pre-fabricatedpaint booths comprising the elements herein described and claimednaturally come within the scope of this invention. While the inventionhas been described with respect to its preferred embodiments, and whilespecific details have been provided to enable those of ordinary skill inthe art to comprehend the involved principles, it would be obvious tothose skilled in the art from the foregoing disclosure that alternateembodiments may be operated in equivalent fashion to that describedherein. Thus the invention is not to be construed as being limited tothe disclosed specifics herein. The invention as herein described isonly limited by the appended claims and equivalents thereof.

What is claimed is:
 1. A closed system for volatile organic compoundrecycling, comprising a sealed spray-booth, at least one airrecirculation housing, and a water decontamination unit, wherein air iscontinually recirculated within said spray booth through an air ventsystem attached to said air recirculation housing, and said airrecirculation housing comprises a mean for removing particulate matterand volatile organic compounds (VOC) from said recirculated air, suchthat said VOCs are condensed into a contaminated water solution andtransferred, through an inlet tube, into said water decontaminationunit, wherein said water decontamination unit comprises a means forremoving said VOCs from said contaminated water solution and a cleanwater solution is transferred, through an outlet tube, from said waterdecontamination unit to an upper fill compartment for reintroductioninto said system, wherein said air recirculation housing comprises anair inlet and air outlet, wherein a contaminated air flow enters saidair recirculation housing through said air inlet, and a clean air flowexists said air recirculation housing through said air outlet, said airrecirculation housing comprises a means for inserting a filter into saidair outlet, such that when a person is within said spray booth, saidfilter is inserted within said air flow, and when said person is notwithin said spray booth said filter is removed from said air flow.
 2. Aclosed system for volatile organic compound recycling, comprising asealed spray-booth, at least one air recirculation housing, and a waterdecontamination unit, wherein air is continually recirculated withinsaid spray booth through an air vent system attached to said airrecirculation housing, and said air recirculation housing comprises amean for removing particulate matter and volatile organic compounds(VOC) from said recirculated air, such that said VOCs are condensed intoa contaminated water solution and transferred, through an inlet tube,into said water decontamination unit, wherein said water decontaminationunit comprises a means for removing said VOCs from said contaminatedwater solution and a clean water solution is transferred, through anoutlet tube, from said water decontamination unit to an upper fillcompartment for reintroduction into said system, said waterdecontamination unit comprising a waste water tank, an ultra violet (UV)light chamber, and a feed tank.
 3. The water decontamination unitaccording to claim 2, wherein said waste water tank comprises a meansfor transferring said contaminated water solution into said UV chamber.4. The waster water tank according to claim 3, wherein said means fortransferring said contaminated water solution to said UV chambercomprises a float activated pump affixed to a spray manifold, whereinsaid spray manifold spans the width of said UV chamber.
 5. The waterdecontamination unit according to claim 3, wherein said contaminatedwater solution entering said UV chamber flows over a substantially flatUV light reflective surface into said feed tank, and wherein said UVchamber further comprises a UV light source.
 6. The UV chamber accordingto claim 5, wherein said substantially flat UV light reflective surfacecomprises an aluminum plate impregnated with a UV light reflectivematerial.
 7. The UV chamber according to claim 6, wherein said UVreflective material is titanium dioxide.
 8. The water decontaminationunit according to claim 5, wherein said feed tank is lined with solventabsorbing liner.
 9. The water decontamination unit according to claim 5,wherein said feed tank contains filters.
 10. The water decontaminationunit according to claim 5, wherein an outlet pump transfers said cleanwater solution from said feed tank into said upper fill compartment. 11.The feed tank according to claim 10, wherein said outlet pump comprisesa removable filter.
 12. An air recirculation housing comprising an airinlet and air outlet, wherein a contaminated air flow enters said airrecirculation housing through said air inlet, and a clean air flow exitssaid air recirculation housing through said air outlet, said airrecirculation housing further comprising a means for inserting a filterinto said air outlet, such that when a person is within said spraybooth, said filter is inserted within said air flow, and when saidperson is not within said spray booth said filter is removed from saidair flow.
 13. A water decontamination unit comprising a waste watertank, an ultra violet (UV) light chamber, and a feed tank, wherein saidUV light chamber comprises a UV light source and a substantially flat UVlight reflecting surface, said substantially flat UV light reflectingsurface being impregnated with a UV light reflecting material, such thata contaminated water solution from said waste water tank spills onto andflows over said substantially flat UV reflecting surface, whilesimultaneously being subjected to a substantially continuous level of UVlight from said UV light source, the contaminated water exiting said UVlight chamber into said feed tank.
 14. The water decontamination unitaccording to claim 13, wherein said waste water tank comprises a meansfor transferring said contaminated water solution into said UV chamber.15. The waster water tank according to claim 14, wherein said means fortransferring said contaminated water solution to said UV chambercomprises a float activated pump affixed to a spray manifold, whereinsaid spray manifold spans the width of said UV chamber.
 16. The UVchamber according to claim 13, wherein said substantially flat UV lightreflective surface comprises an aluminum plate impregnated with said UVlight reflective material.
 17. The UV chamber according to claim 16,wherein said UV reflective material is titanium dioxide.
 18. The waterdecontamination unit according to claim 13, wherein said feed tank islined with a solvent absorbing liner.
 19. The water decontamination unitaccording to claim 13, wherein said feed tank contains filters.
 20. Thewater decontamination unit according to claim 13, wherein an outlet pumptransfers said water solution from said feed tank into an upper fillcompartment.
 21. The feed tank according to claim 20, wherein saidoutlet pump comprises a removable filter.